Stalled cycle?

[Sierra23]

Can someone help me understand what it means when ammonia/nitrite/nitrate in a previously cycled tank are all now at 0? For several days in a row.
(2 guppies introduced 10 days ago to a 10 gal tank. Was at 0 ammonia, 0 nitrite, 5-10 nitrate when introduced. Water change when ammonia increased to 0.25. One guppy died 4 days ago....I suspect he was ill when I brought him home. Remaining guppy seems ok right now). Trying to understand how I can have no ammonia build up at all even with a fish in there. And what do I do now to make sure the cycle is done correctly, with a fish in the tank?
And is a tank truly cycled if you never see any nitrites at all?

 

[paytertot]

When a tank is fully cycled, there should be 0 ammonia and 0 nitrites but you will see varying levels of nitrates. However you want to keep them low. So are you seeing 0 nitrates as well or just low levels?

 

[Sierra23]

I am now seeing 0 nitrates. It had been very low but now has been 0 across the board for 4 days.

 

[paytertot]

That's strange. But there are also 0 ammonia and nitrites? Same test kit? Only 2 guppies in there, that's not going to keep a good cycle going, not enough waste. It'll drop your amount of good bacteria and you'll have to be very careful adding fish in the future. But I'm not sure why they're all 0, I've been out of the game a while so I'd wait for better advice.

 

[pradeepcec]

Ammonia increase to 0.25? I guess that should never happen, if it is happening then probably your cycle is not complete or something went wrong killing all the beneficial bacteria.

 

[Sierra23]

So nevermind...looks like my tank is not properly cycled. Ammonia went from 0 yesterday to 0.5-1 today. Did a big water change. I assume I start over as if a fish-in cycle? Did I not wait long enough to introduce fish? Parameters were steady at 0 ammonia, 0 nitrite and 5-10 nitrate for over a week before bringing the guppies home

 

[paytertot]

Were you continuously adding ammonia before you added the fish? If there was a period of no ammonia input, your good bacteria may have died off. I'd say you're re-cycling now.

 

[54seaweed]

So nevermind...looks like my tank is not properly cycled. Ammonia went from 0 yesterday to 0.5-1 today. Did a big water change. I assume I start over as if a fish-in cycle? Did I not wait long enough to introduce fish? Parameters were steady at 0 ammonia, 0 nitrite and 5-10 nitrate for over a week before bringing the guppies home

you can see ammonia also depending on the load of fish you added at once you need to remember new tanks build bb over time you may have overloaded it to fast
did you take that into account

 

[Sierra23]

Were you continuously adding ammonia before you added the fish? If there was a period of no ammonia input, your good bacteria may have died off. I'd say you're re-cycling now.

Maybe that's my issue. There was a period of 3 days or so where I didn't add ammonia right before I added fish. If a small or unstable population, maybe they died off?

 

[Sierra23]

you can see ammonia also depending on the load of fish you added at once you need to remember new tanks build bb over time you may have overloaded it to fast
did you take that into account

I only added 2 guppies to start. Didn't think that would be too much for 10 gallons?

 

[paytertot]

Maybe that's my issue. There was a period of 3 days or so where I didn't add ammonia right before I added fish. If a small or unstable population, maybe they died off?

Yeah basically they starve

 

[paytertot]

I only added 2 guppies to start. Didn't think that would be too much for 10 gallons?

The size of the tank doesn't really matter, they're referring to the amount of bacteria you had acquired. But I think it was the opposite problem, I think you lost your BB.

 

[Sierra23]

Ok. Thanks everyone for the help. Live and learn!

 

[paytertot]

So how's it going now?

 

[Sierra23]

Well.....the ammonia spiked to almost 4.0 ppm. No nitrite or nitrate. So given that my tank is obviously not cycled and I lost 1 guppy already, I brought the remaining guy back. Didn't want to kill him too :-/
So I'm going to start over. I did a couple water changes so that now ammonia is about 2. Would tetra safe start be helpful here? And then just monitor parameters while adding small bits of food?
Thanks for all your help guys. Really appreciated.